Veterinarian View | March 2025

Diagnosing Sick Neonatal Calves

contributed article by Dr. Vince Collison, Collison Embryo and Veterinary Services,

Rockwell City, Iowa

As we start the calving season, there are always going to be calves that need extra attention. The most common diseases are usually related to respiratory or enteric (diarrhea) causes. Navel infections can also cause a variety of symptoms which can also progress to arthritis, diarrhea, or septicemia. When we are called out to examine sick baby calves, symptoms can vary widely but it is always a good time to review what to look for so that calves can be treated as early as possible and issues addressed, so a game plan can be formed for prevention and treatment.

Calf is Slow

This is probably one of the most common symptoms but can tend to be ignored because it is a symptom that doesn’t easily relate to a direct cause. When I see a calf that is not active within the first 10 days, I will assume that this calf is septic, unless there are other symptoms going on related to respiratory causes.

Septicemia is a fairly common thing to see in this age of calf and it just means an infection that is in the blood and causing symptoms of depression. Probably the most likely source of septicemia is when bacteria enter through the newborn’s fresh navel. This can cause symptoms right away, but I’ve seen it take up to 10 days to develop. This does not necessarily have to be related to a swollen navel. One of the tip offs can be that the cow has a swollen bag due to the calf not nursing.

Calf is Thumping

When a calf is having rapid exaggerated respiratory efforts, producers can assume it is pneumonia. Many times, this is caused by pneumonia, but there are two other causes to consider as well.

When calves get diarrhea, they will lose a lot of sodium bicarbonate from their system. This causes the calf to go into a secondary condition called metabolic acidosis. This means that the blood is becoming more acidic than normal, and the normal physiological response is to breath more rapidly.

By breathing more rapidly, they are trying to blow off carbon atoms through the respiratory system via CO2 to balance the body pH back up to a normal level. When we see this in conjunction with diarrhea, it’s important to use an electrolyte product that contains sodium bicarbonate to help balance the pH back to normal.

I find that a lot of producers are using electrolyte products that do not have anything to correct for acidosis and do not see improvement in conditions. Acidosis will also cause the depression on the diarrhea calves. Usually, you will see rapid improvement from the depression once the acidosis is corrected.

The third cause of rapid breathing is from vitamin E/selenium deficiency. When a calf becomes deficient it causes white muscle disease and one of the first muscles it affects is the diaphragm. This weakness in the diaphragm leads to rapid breathing.

Calf has Ear Down

When a calf has an ear down, it is probably fighting an inner ear infection, but there is almost always a respiratory component going on as well. The most common infections related to dropped ears are Mycoplasma bovis, Mannheimia hemolytica, and Histophilus somnus. All of these are very common in respiratory infections as well. I will usually treat these with the same antibiotics that are commonly used for pneumonia. If we see these infections move into the ear, we assume they will move into the lungs as well.

Calf has Diarrhea

This is something that can vary quite a bit in severity. Many of these calves can be treated with a minor treatment and will respond well. If the calves get very loose and have watery diarrhea, they probably will need some fluid therapy with electrolytes. As stated earlier, if the calf is very depressed, it probably has acidosis that needs corrected as well. Causes of diarrhea are kind of related to the age of the calf at onset. E. coli and Clostridium perfringens type C are some of the first infections you will see and can start within one or two days of birth and can be seen at any age of calf.

Rotavirus is usually not seen until 10 to 14 days of age and Corona virus is seen around three weeks of age. Coccidia is something that won’t be seen until the calf is about 30 days old, this is how long the life cycle of Coccidia takes to become symptomatic in calves. If you see blood in a calf’s stool at less than 30 days of age, there is probably something else causing the symptoms other than Coccidia.

Cryptosporidium is an infection we will see in any aged calf. E. coli, Clostridium and Cryptosporidium can all show flecks of blood in the diarrhea they cause, and all of these infections can get misdiagnosed as Coccidia in some of these younger calves because of the blood.

Calf has a Swollen Navel

This is often due to navel infection that starts at birth in the umbilical cord. Calves may also show a wet weepy navel associated with umbilical infections. Usually these are hard and swollen and the calf will show pain when you squeeze the navel. This type of infection needs to be treated with antibiotics and usually requires some duration of treatment to get cleared up.

The other thing you will see with swollen navels is an umbilical hernia. These will be very soft and full of intestines. When squeezed, the intestines will go back up into the abdominal cavity and the opening of the hernia can easily be felt. There is really no treatment for these other than surgery to correct the hernia.

Success with hernia surgery is probably best when the calf is younger and will have less body weight on the surgical site. As these calves get bigger it becomes more challenging to correct these hernias due to increased size and body weight. It is possible to see hernias concurrent with navel infections and is probably the cause of the hernia due to the infection preventing the closure of the umbilical stump after being born.

The key to recovery is to treat as early as possible. Symptoms can start out very subtle so recognizing issues early can make a big difference in treatment success.

learn more www.collisonembryoservices.com

Dr. Vince Collison is co-owner of Collison Embryo and Veterinary Services PAC

in Rockwell City, Iowa.